The work culture of the OE developers, frequenting IRC and mailing lists, is vastly different from that of the pdaXrom developers, who gravitate around OESF Forums. I gathered the following OE related links to keep them handy.
Build Env
OE mailing list: Dev, Issue, Commit, User, and Announce; bug trackers: OE for cross-compiling and packaging. (Handhelds only for binaries handhelds.org ships.)
Distro
Angstrom mailing list: Dev, and User.
Open Zaurus mailing list: Dev, Software, User, and Announce.
UI
GPE mailing list: User, Commit, Bug, Translation, and bug tracker.
OPIE mailing list: Dev, Commit, Bug, User, and bug tracker.